Diamidodiphenylamin sulfonic acid and process of making same.



NITED STATES 7 PATENT OFFICE;

FRIEDRICH SCHMIDT, OF HUOHS'PON-THE-MAIN, GERMANY, ASSIGNOR TO THE FARBWERKE, VORMALS MEISTER, LUCIUS dz BRllNING, OF SAME PLACE.

SPECIFICATION forming part of Letters Patent No. 647,237, dated April 10, 1900.

Application filed March 15, 1899.

To all whom it may concern.-

Be it known that I, FRIEDRICH SCHMIDT, Ph. D., a citizen of the Empire of Germany, residing at Hochst-on-the-Main, Germany,

have invented certain new and useful Im provements in the Manufacture of Diamidodiphenylamin Disulfonic Acid and A Dyestuffs Therefrom, of which the following is a specification.

to I have found that nitrochlorbenzene sulfonic acid of the constitution The constitution of the new acid is:

NH, NH,

Example I.One hundred and fifty kilos of para-phenylenediamin sulfonic acid ,two hundred kilos of para-nitrochlorbenzene sulfonic 5o acid, one hundred kilos of soda, and one th ous'eriaino. 709 189. (Specimens-l sand kilos of water are boiled for six hours in a vessel provided with an inverted condenser. The brown-yellow solution thus obtained is acidified with hydrochloric acid, whereupon amidonitrodiphenylarnin disulfonic acid, at first formed, separates as a thick greyish yellow precipitate. It is filtered, pressed,and reduced in the usual manner with iron and acetic acid. The liquid of reduction, made alkaline with soda, having been filtered from the iron, diamidodiphenylamin disulfonic acid is precipitated by an addition of mineral acid. It separates as a greyish-white crystalline precipitate which is insoluble in an excess of hydrochloric acid. The acid is soluble with difficulty in water. It is easily diazotized and forms a yellow tetrazo compound, soluble with difliculty, which combines with the usual components to form valuable azo dyestuifs characterized by their solubility and the fastness of their tints.

Example II-llfanufacture 0 a black direct dyeing cotton dyestufi 0f the constitution:

Amidonaphtholsulfonic acid G-meiaphenylenediamin 7 5 Diamidodiphenylamin disulfom'c acid Amidonaphtholsulfon'ic acid G-metaphenylenediamim- 35.9 kilos of diamidodiphenylamin disulfonic acid are dissolved in 24.0 kilos of caustic-soda 8o lye of 40 Baum and one thousand liters of water, to which are added 13.8 kilos of nitrite. The whole is run, while stirring, into 60. 0 kilos of hydrochloric acid, 22 Baum, diluted with two hundred liters of water. The yellow-col- 8 5 cred tetrazo compound, soluble with difliculty, which is at once formed, is run into a solution of forty-eight kilos of amidonaphtholsulfonic acid G in forty kilos of soda and one thousand liters of water, when a violet dyestuft (diami- 9o dodiphenylamin disulfonic acid 2 amidonaphtholsulfonic acid G) is obtained, which remains dissolved in the liquid. This dyestufii is again diazotized by first adding seventy kilos of hydrochloric acid to the violet solution, whereupon the color becomes a pure blue, and then 13.8 kilos of nitrite are added. Finally, twenty-two kilos of meta-phenylenediamin, dissolved in five hundred liters of water, are added, so as to form the black dye- I00 sta e Diamz'dodiphenylamin disulfonic acid Metaphenylenediamin.

The tetrazo compound obtained from 35.9 ki-' los of diamidodiphenylamin disulfonic acid is poured, while stirring, into a solution of twenty-two kilos of meta-phenylenediamin at 40 centigrade in five hundred liters of water. A brown precipitate is formed at once, consisting of the free dyestuft acid. When heated with twenty kilos of soda or twentyfour kilos of caustic-soda lye, 40 Baum, it dissolves With a red-brown color, and on addition of salt is again precipitated as sodium salt, easily soluble. The dyestuff yields on unmordanted cotton in a weak alkaline bath red tints, which when treated with acids become violet and with diazonitrobenzene a very fast deep brown.

By employing meta-toluylenediamin in- I claim is- 1. A process for the manufacture of diamidodiphenylamin disulfonic acid, which consists in condensing molecular quantities of para-chlornitrobenz'enesulfonic acid or its salts with para-phenylenediaininsulfonic acid or its salts and subsequent reduction,substantially as described. I

'2. As new product the diamidodiplienylamin disulfonic acid, being a greyish-white powder, in form of its free acid soluble with difficulty or insoluble 'in water, alcohol, 860., forming in water with alkali carbonate or alkali lye easily soluble alkali salts from the aqueous solutions of which on addition of mineral acid the free diamidodiphenylamin disulfonic acid is again precipitated, forming with nitrous acid a yellow-colored tetrazo compound soluble with difliculty, yielding with the usual components valuable dye stufis.

In testimony that I claim the foregoing as my invention I have signed my name in pres ence of two subscribing witnesses.

FRIEDRICH SCHMIDT.

Witnesses HEINRICH HAHN, BERNHARD LEYDEOKER. 

